1. Field of the Invention
The present invention relates generally to article handling apparatus and, more particularly, to such apparatus employing an air stream for orienting or classifying articles having surface areas which differ significantly in continuity or roughness.
2. Description of the Prior Art
It is known in the art to use air pressure in various types of article handling apparatus. In some cases a pressure differential is used to actuate solenoids, pistons, valves and the like. In others, an air stream interacts directly with the article to affect its position or condition. For example, U.S. Pat. No. 3,734,268 discloses an assembly for orienting lids having a cupped rim or skirt. An air nozzle directs a stream of air against the lid to flip "skirt-down" articles to a "skirt-up" position, without disorienting articles already in the "skirt-up" position. In this case the lids have the characteristic configuration of the cupped rim or skirt, and the air nozzle can be positioned to direct an air stream to contact an outer portion of the skirt to induce a flipping action thereto. When the article is already in the skirt-up position, on the other hand, the air stream acts upon a lesser area, resulting in only a slight lifting action which is not sufficient to flip the skirt-up article. Such apparatus is apparently suitable for orienting lids and similar articles having the required surface configuration, but it is not suitable for a number of other articles of different configurations, such as flat elements, with which the present invention has particular utility. As another example, U.S. Pat. No. 3,307,678 discloses bobbin handling apparatus for orienting bobbins which have a characteristic configuration of one open end being larger than the other end. The bobbins are uniformly oriented by providing a pair of air nozzles which produce air streams cooperating to flip improperly oriented bobbins to the desired orientation. The air stream takes advantage of the characteristic configuration of the bobbin and, like the lid orienting apparatus discussed above, the disclosed bobbin handling apparatus would appear to be limited to handling and orienting objects of a particular configuration.